Sheet delivery unit



June 27, 1967 J. G. SCHMIDTKE 3,328,027

S H E E T D E L I V E R Y U N IT I Filed May 24, 1965 2 Sheets-Sheet 1iNVENTOR JemzH/zw 4%. SQ'HMIQTAE\ June 27, 1967 G, scHmm-K'E- 3,328,027I I SHEET DELIVERY UNIT Filed May 24, 1965 1 2- Sheets-$heet FIG?)INVENTOR JMtI/IM G. scmmo'm'z ATTORNEY United States Patent 3,328,027SHEET DELIVERY UNIT Joachim G. Schmidtke, 22518 Mylls, St. Clair Shores,Mich. 48081 Filed May 24, 1965, Ser. No. 458,337 4 Claims. (Cl. 271-68)This invention relates to a delivery unit operative to receive sheets ofmaterial such as paper and the like from a processing unit and to stackthe sheets one above the other.

The present invention is useful in connection with a Wide variety ofoperating machines such as bronzing machines, presses, shears, and thelike, used in graphic arts and other industries, which provide as theiroutput a series of relatively large thin sheets. If these sheets arerelatively short they may be directly received in a pile on'top of theskid. The skid may be lower in timed relation to the feed of sheets fromthe machine in order to maintain the top of the stack at approximatelythe delivery level. When the sheets are relatively long, the force withwhich they are rejected from the bronzing machine or other similar unit,may not be sufiicient to cause them to move through the entire width ofthe stack under their own power. The situations in which this problemoccurs aredependent upon the width, weight, and thickness of the paper,and the manner in which it is ejected from the operating machine. Whenadditional energy must be imparted to the sheets in order to cause themto stack regularly it is the present practice to employ what are termedejection tapes. These tapes consist of a conveyorlike arrangement ofnarrow closed loops which are disposed immediately below the ejectionlevel of the operating machine and which support the sheets on theirunderside and impart sufiicient energy to the sheets so that they willshoot across the width of the previous sheets so as to neatly stackthereon.

The present invention is addressed to those situations where the widthof the sheet being operated upon is sufficiently great and the sheet issufliciently thin so that ejection tapes will not cause the ejectedsheets to move across the width of the stack with sufficient energy toinsure a neat stack. In essence it consists of a conveyor beltcomprising a number of closed loops which are disposed parallel to theejection tapes with one end over the output end of the ejection tapesand the other end over the final stack. Unique vacuum means are providedto attract the forward edge of a sheet passing over the ejection tapesto this upper conveyor. The conveyor then carries the sheets over thestack and releases them so that they pile up neatly.

In a preferred embodiment of the invention, which will subsequently bedescribed in detail, the operating unit in connection with which theinvention is employed, is a bronzing machine. This unit delivers theforward edge of its output sheets to the beginning of a group of closedloop ejection tapes moving in lines parallel to the direction ofdelivery of the sheets. A plurality of closed loop over head vacuumbelts extend from a line adjacent to the output ends of the ejectiontapes across the major part of the width of the stack. These tapesconsist of elongated closed loop belts with perforations at regularintervals which rotate about a pair of parallel separated axes disposedin the horizontal plane. The lower side is active and contacts the paperand the upper side is simply the return. On the lower side the beltmoves through an elongated vacuum manifold. The manifold acts to draw inair through the perforations in the belt. A vacuum pressure connectionis made to the manifold adjacent to the end disposed over the ejectiontapes so that a maximum suction is exerted on sheets at that end and theforce of reice tention of the sheets decreases along the length of thebelt to a level insufficient to support the sheets at the extreme endadjacent to the forward end of the paper stack.

The vacuum belts are moved in synehronism with the ejection tape so thata sheet delivered to the ejection tapes from the machine moves acrossthe length of these tapes and is then picked up by the rear edge of thevacuum belt and lifted and carried across the width of the sheet stack.As the forward edge of the sheet approaches the end of the stack, itbegins to drop oif and fall on top of the previously stacked sheets.

As the sheet reaches this position an air blast is directed at the sheetfrom positions intermediate on the vacuum belts. This blast isdownwardly directed and acts to free the sheet from the vacuum belt andmove it downwardly onto the stack. The air blast is actuated byphoto-electric detection means which senses the approach of the forwardend of the next sheet into position with respect to the forward end ofthe vacuum belts.

The stack incorporates previously known means to lower a supporting skidin timed relation to the addition of sheets to the top of the stack inorder to maintain the stack height at proper delivery height, as well asjogger means which bear against the edge of the stack to maintain it inan aligned manner.

It is therefore seen to be a primary object of the present invention toprovide a delivery system for a machine operating upon sheet goods whichincludes a moving vacuum belt system disposed above the delivery heightof the sheets operative to draw the sheet upwardly and convey them overa stack of previously delivered sheets and then to deposit them on thisstack.

Another object is to provide such a system wherein the upwardly actingvacuum force exerted on the sheets decreases as the sheet becomesproperly positioned over the stack and positive ejection means areemployed to separate the sheet from the vacuum belt at the proper point.

Another object is to provide such a system wherein ejection tapes areemployed to convey the sheets from the operating machine and a vacuumdelivery belt is disposed parallel to the ejection tapes with one endover the forward end of the ejection tapes and its other end near, butseparated from, the forward end of the stacked sheets.

Another object is to provide such a delivery system wherein the vacuumbelt consists of a closed loop of belt having regular perforationstherein which moves in a closed return path over a pair of end rolls andwherein a manifold is provided for the lower side of the belt, themanifold having a vacuum inlet which is exhausted. through theperforations of the belt.

A still further object is to provide such a system wherein the positiveejection means consists of an air blast triggered by a photo-electricsensing mechanism which detects the position of the sheet with respectto the stack.

Other objects, advantages and applications of the present invention willbe made apparent by the following detailed description of a preferredembodiment of the invention. The description makes reference to theaccompanying drawings wherein:

FIGURE 1 is a perspective view of a delivery system formed in accordancewith the present invention; FIGURE 2 is a side view of the deliverysystem of FIGURE 1;

FIGURE 3 is a longitudinal sectional view through the vacuum tape takenalong lines 33 of FIGURE 2; and

FIGURE 4 is a transverse sectional view through the vacuum tape takenalong lines 44 of FIGURE 3.

Referring to the drawings, the preferred embodiment of the deliverysystem is shown as receiving the output of an operating machine 10. Ideveloped the delivery system of the present invention for specific usein connection with a bronzing machine which forms metallic decoration onpaper, but the delivery system is equally applicable for use with othermachines employed in the graphic art industry which operate on separatedsheet material as opposed to material in a continuous roll form. Forexample the delivery system might be useful in connection with printingpresses, shearers, embossing machines, and the like. The delivery systemis also useful in connection with machines in other industries whichoperate on relatively large sheets, whether the material of the sheetsbe paper or cloth, plastic, and the like.

The machine regularly feeds out paper 12 cut in regularly relativelywide, sheets. The object of the delivery system is to neatly stack thesheets 12 on a pallet 14. Forces generated by static electricity preventthe proper stacking without the provision of additional powering means.While the solution to the problem might lie in providing additionalenergy to the ejection system to the machine 10, if the sheet issufiiciently thin and light in weight, the amount of energy of motionwhich may be imparted to it is limited and relatively small compared tothe resistance encountered in motion through the air.

The delivery system of the present invention is supported between a pairof elongated vertically aligned side plates 16 which are supported onthe frame of the machine 10 at one end and on vertical posts 18 at theother end. The side plates 16 are aligned parallel to one another and tothe direction of feed of the sheets 12 from the machine 10 and aredisposed about the same height as the sheets 12 are delivered from themachine 10, preferably extending both above and below this deliveryheight. At their extreme forward ends (the ends opposite to the machine10) they support a vertical plate 20 which extends transversely to theaxis of delivery of the sheets 12 and constitutes a backing plate whichthe forward edges of the sheets abut to terminate their forward motion.The backing plate 20 is disposed at slightly below the height ofdelivery of the sheets from the machine as they move downwardly slightlyduring their motion from the machine to the backing plate.

Immediately forward of the line at which the sheets 12 are rejected fromthe machine 10, the side plates 16 support an ejection tape systemgenerally indicated at 30. The ejection tapes 32 which form part of thissystem consist of elongated closed loop bands of relatively narrowmaterial preferably having a high friction surface. Nine ejection tapes32 are employed in the preferred embodiment and they are arrayed inthree groups of three each. The loops are journalled at their rear endson pulleys 34 which are rotatably supported on a shaft 36 having itsends fixed in the two opposed side plates 16. The shaft 36 extendsnormally to the axis of ejection of the sheets 12 from the machine 10.The other ends of the ejection tapes 32 are formed about nine pulleys 38which are larger than the pulleys 34 and which are fixed to a rotatingshaft 40*.

One end of the shaft 40 passes through one of the side plates 16 and isconnected to a motor drive system 42 of any suitable type. In thepreferred embodiment this drive system rotates the shaft constantly butin other embodiments of the invention it might be intermittently rotatedor might be driven off of the serviced machine 10. The upper edges ofthe drive pulleys 38 and the driven pulleys 34 lie in the samehorizontal plane so that the top edges of the ejection tapes 32 extendhorizontally. The drive pulleys are relatively larger than the drivenpulleys 34 in the preferred embodiment to provide a sufficient degree ofdriving friction.

The overhead vacuum tape system generally indicated at 50 consists of apair of thin elongated belts 52 journalled about a pair of rear drivingpulleys 5'4 and a pair of smaller driven pulleys 56. The driven pulleys56 are rotatably supported on a shaft 58 journalled in the side plates16 and extending transversely to the axis of sheet feed. The drivingpulleys 54 are fixed to a rotatable shaft 60 that passes through thewall of one of the side plates and is also powered by the motor drivesystem 42 at the same speed as the ejection tapes system 30.

The shaft 60 is positioned above the tapes 32 and slightly behind theshaft 40. The fixed shaft 58 is disposed near the forward edge of thestack of previous sheets 12 which are disposed on the pallet 14. Theheights of the pulleys 54 and 56 are arranged so that the lower sides ofthe belts extend in the horizontal plane. Because of the location of thepulleys the belts extend from a point slightly to the rear of theforward edge of the tapes 32 almost across the entire width of the stackof sheets 12. The belts 52 each consist of a relatively wide base member64 with a narrower section 66 attached to one side and extending downthe middle of the belt. The relatively wide backing member 64 may beformed of canvas or other conventional belt material and is preferablychosen for its strength and long life. The extending section 66 ispreferably formed of felt or other soft material which may be broughtinto intimate contact with a paper sheet. A pattern of perforations 68is formed through both the backing belt 64 and the extending section 66regularly along the center of the belt.

The lower sides of the belts 52 pass through a pair of vacuum manifoldchannels 72 which extend in the horizontal plane between the pulleys 54and 56. The channels 72 are supported under a pair of cross members 74which extend between the side plates 16. The channels have a basic Uconfiguration with inturned flanges 78. A pair of inner flanges extendinward partially across the section of the channel 72 spaced from theflanges 78. The backing section 64 of the belt is slightly thinner thanthe space between the flanges 78 and 80 and rides through this space.

The extending section 66 of the belt passes through the aperture betweenthe opposed edges of the inturned flanges 78 and has a thickness greaterthan those flanges so that its surface extends beyond their surfaces.The upper section of the manifold is filled with a stiffening material82 which extends to a level slightly separated from the upper edge ofthe internal flanges 80. The space between the upper sides of theflanges 80 and the bottom of the material 82 forms a vacuum chamber.

A blower unit supported on one of the side plates 16 draws in air so asto produce a vacuum within the space between the flanges 80 and thestiffening material 82 by means of tubes 92 which connect throughapertures 94 on the top side of the channel members at points adjacentto the ends associated with the pulleys 54. The channel member acts as amanifold to draw air through the aperture 68 in the belt. A strongersuction exists at the ends of the belts adjacent to the connections tothe tubes 92 than at the other extreme ends adjacent to the pulleys 56and the force of suction tapers along the belt.

Two pairs of air ejection members and 102, 104 and 106 are supported ontop of the two manifold vacuum channels 72. The units 100 and 104 arelocated adjacent to one end of each of the channels and the units 102and 106 are located adjacent to the opposite end. These units eachinclude extending pipes 108 which project outwardly on both sides of thechannel members. The pipes contain holes on their lower sides. The unitsreceive air from a blower unit 110 at appropriate controlled intervals.When air is passed to the tubes 108 a downward force is exerted on asheet held by the vacuum belts and the sheet is ejected onto theprevious stack of sheets 12. The ejection of air through the pipes 108is controlled by a photo cell unit 114 which senses the end of a sheetbeing fed on to the vacuum units by the ejection tapes. The photo cell114 is located above the sheets adjacent to the forward end of thedelivery system. When it senses the front of the following sheet andactuates the blower 110 to provide an air blast through the pipes 108the sheet in the vacuum belt is ejected therefrom.

In operation, the leading edge of a sheet 12 fed out of the operatingmachine by suitable mechanism associated with that machine (not shown)falls on to the rear end of the ejection belts 32 and is carried forwardalong the belts, by their motion, until the forward edge of the sheet isin proximity to the rear edges of the vacuum belts 52. The lower sidesof the vacuum belts are spaced with respect to the upper surfaces of theejection belts 32 so that the forward edge of a sheet is drawn upwardlyagainst the extending sections 66 of the vacuum belt. The soft surfaceof each belt allows the sheet to at least partially seal off the vacuumaperture 68 in the belt. As succeeding elements along the sheet reachthe vacuum, belt, they too are drawn up until the entire length of thesheet is in contact with the belt.

By this time the forward edge of the sheet has reached a section of thevacuum belt adjacent to the end of the manifold 72 quite removed fromthe vacuum source 99. Accordingly the suction becomes insutficient tomaintain the forward edge and, as is seen in FIGURE 2, the forward edgebegins to fall from the manifold against the paper stack. When thetrailing edge of the sheet reaches the photocell ar'nangement 114 an airblast is initiated through the pipes 108 causing a downward force on theentire sheet which overcomes the suction force and blows the sheetdownwardly on the top of the stack. This ejection point may come justbefore the forward end of the sheet reaches the forward end of the pilebecause of the inertia of the sheet. The forward end of the sheet shouldhave sufficient force to abut the stop plate 20 so as to position thesheet with respect to the stack.

The exact stack arrangement does not form part of the present inventionbut the unit employed in connection with the preferred embodiment of theinvention incorporates an edge aligning unit 150 consisting of a flatplate which abuts the rear end of the sheet is energized by a suitableactuator 152 so as to bear against these edges of the sheet and alignthem against the backing plate 20. The pallet 14 is supported on alowering mechanism which includes a pair of parallel bars 156 disposedunder opposed edges of the pallet. The bars are supported by mechanismwhich is adapted to lower them in timed relation to the addition ofsheets to the stack in some suitable manner. This mechanism maintainsthe stack height of the sheets at the same delivery point independentlyof the number of sheets in the stack.

Having thus described my invention, I claim:

1. A delivery system for an operating machine which delivers cut sheetsat a delivery height, the system being operative to remove the sheetsfrom the machine and to stack them one above the other, comprising: aplurality of elongated, closed loop ejection belts disposed with theirupper sides just below the delivery height; means for rotating saidbelts so as to move sheets delivered to their input side toward theiroutput sides; an array of closed loop vacuum belts having a plurality ofclosely spaced apertures formed therein disposed with an input sideabove the output side of a set of ejection belts, and parallel to saidejection belts; means for continuously drawing air through all theapertures in the lower section of said vacuum belts so as to draw sheetsdisposed on the output end of the ejection belts to the input end of thevacuum belts; means for rotating the vacuum belts to move the sheetdisposed at the input end across the vacuum belts; a separate ejectionmeans disposed adjacent said vacuum belts to their output ends andoperative simultaneously with the means for continuously drawing airthrough all the apertures to provide a force to sheets supported by saidvacuum belts in the direction away from the vacuum belt; and a stackoperative to receive successive sheets delivered from said vacuum belt.

2. The system of claim 1 wherein the ejection means comprise ejectionnozzles attached to an air supply operative to provide an air blastagainst the sheets retained in the vacuum belt upon receipt of anappropriate control signal.

3. The structure of claim 1 wherein the means for drawing air throughthe lower side of the vacuum belts consists of a manifold surroundingthe upper side of the vacuum belt and means for drawing air from themanifold so as to cause a flow of air inwardly through the lower side ofthe vacuum belts.

4. The structure of claim 1 wherein each of the vacuum belts has arelatively wide backing section and a relatively narrow extendingsection centered on the outer side of the backing section and theapertures are formed through the backing section and the extendingsection and the means for continuously drawing air through the aperturesconsists of manifolds associated with each of the belts, each manifoldhaving a generally downturned U configuration with inturned flanges onthe extreme ends surrounding the belts so that the extending section ofthe belt passes between the aperture and the flanges.

References Cited UNITED STATES PATENTS 1,401,366 12/1921 Sargent 198-2042,895,552 7/1959 Pomper et al. 27l-74 X 2,897,952 8/1959 Buccicone 27l69X 3,079,150 2/1963 Lopez 27l69 3,123,354 3/1964 Ungerer 27l74 3,262,6997/ 1966 Aschenbrenner 27l69 X M. HENSON WOOD, JR., Primary Examiner.

J. N. ERLICH, Assistant Examiner.

1. A DELIVERY SYSTEM FOR AN OPERATION MACHINE WHICH DELIVERS CUT SHEETSAT A DELIVERY HEIGHT, THE SYSTEM BEING OPERATIVE TO REMOVE THE SHEETSFROM THE MACHINE AND TO STACK THEM ONE ABOVE THE OTHER, COMPRISING: APLURALITY OF ELONGATED, CLOSED LOOP EJECTION BELTS DISPOSED WITH THEIRUPPER SIDES JUST BELOW THE DELIVERY HEIGHT; MEANS FOR ROTATING SAIDBELTS BELOW SO AS TO MOVE SHEETS DELIVERED TO THEIR INPUT SIDE TOWARDTHEIR OUTPUT SIDES; AN ARRAY OF CLOSED LOOP VACUUM BELTS HAVING APLURALITY OF CLOSELY SPACED APERTURES FORMED THEREIN DISPOSED WITH ANINPUT SIDE ABOVE THE OUTPUT SIDE OF A SET OF EJECTION BELTS, ANDPARALLEL TO SAID EJECTION BELTS; MEANS FOR CONTINUOUSLY DRAWING AIRTHROUGH ALL THE APERTURES IN THE LOWER SECTION OF SAID VACUUM BELTS SOAS TO DRAW SHEETS DISPOSED ON THE OUTPUT